This study reports on oncology professionals' knowledge and attitude toward complementary and alternative medicines (CAM), classified according to their primary application as complementary or alternative methods. In June 2002, we conducted a national, multicentre survey of 828 Norwegian oncologists, nurses, clerks and therapeutic radiographers. A response rate of 61% was achieved. Only a few physicians (4%) described their reactions to alternative medicine as positive compared with nurses (33%), therapeutic radiographers (32%) and clerks (55%) (P<0.0001). Females showed a more positive view than males (33% versus 14%, P<0.0001). More participants expressed a positive attitude to complementary versus alternative medicines. Most respondents regarded healing by hand or prayer, homeopathy, and Iscador (mistletoe) as alternative therapies. In contrast, most respondents classified acupuncture, meditation, reflexology, music/art-therapy, aromatherapy and massage as complementary therapies. This survey demonstrates major differences, by gender as well as oncology health profession in views about and the classification of various CAM methods.